INSECTS 239 



discoverer of this case of mimicry. 1 He says that the species 

 is confined to wooded districts, but the female is much less 

 frequently seen on the wing than the male. The latter is 

 exceedingly conspicuous in flight, only occasionally halting at 

 flowers. It returns repeatedly over the same ground in the 

 neighbourhood of a female who remains settled in some shady 

 spot among the weeds and hushes. As the afternoon draws on 

 the female leaves her retirement and flutters slowly about. 

 She is always much slower on the wing than the male, and 

 stays much longer at the flowers she visits. Trimen noticed 

 that she was especially fond of the white flowers of a low- 

 growing labiate. On the other hand, the brown and yellow 

 ochre colouring of the under side of the wings in the male 

 serves well to protect him from observation when at rest 

 among withered foliage. Thus we have the pale yellow of 

 the upper side of the wings in the male developed under 

 bright sunlight, the duller browner colours of the lower side 

 in the neighbourhood of withered foliage, the sombre-tinted 

 female in shady spots among bushes. The wings of the 

 female have degenerated in size and power in comparison 

 with those of the male, as a result of the activity of the latter 

 and the inactivity of the former. 



The argument would be still stronger if it could be shown 

 that the imitated species of the Danaidse had habits similar 

 to the female P. cenea, and different from those of the male of 

 that species. To a certain extent this can be shown. The 

 first form of P. cenea, female, is the commonest, and the 

 following is the account given by Trimen and Bowker of 

 the habits of Amauris echeria, the Danaid which it mimics. 

 This butterfly is rather gregarious, is strictly confined to 

 woods and copses, its flight is remarkably graceful and 

 leisurely, it is fond of floating across open spots in the woods, 



1 Trimen and Bowker, South African Butterflies, London 1889, vol. iii. 

 p. 254. 



